DNA Transcription
We will now turn our discussion to how the genetic material contained in DNA is
stored and used in cells after it has been synthesized during replication. DNA
transcription is the process in which DNA is copied into RNA; as a result the
process can also be called RNA synthesis.
RNA, like DNA, is a complex nucleic acid and is used in cells to help synthesize
proteins that perform various cellular functions. Transcription is critical
because it is a process that helps mediate the expression of genetic material
contained in DNA. A DNA sequence provides the blueprint that during
transcription is coded into a RNA sequence. The RNA product of transcription
then transfers the information from the DNA sequence into a functional protein.
Our discussion will follow the three main steps in the transcription process
initiation, elongation, and termination--and discuss the molecules and enzymes
that mediate the chemical reactions that take place. Our discussion will
address the process of transcription in more simple organisms (prokaryotes) as
well as in more complex organisms (eukaryotes).